SQL Developer won't show the connections Tab

You can go to the upper tab "WINDOW" and then click "Reset Windows to factory settings".

1.) Save your current SQL connection xml file located in windows 7/8/10: C:\Users\"youruseraccount"\AppData\Roaming\SQL Developer\systemXXXXX\o.jdeveloper.db.connection.xxxxxx

2.)Now delete your SQL Developer Folder and sqldeveloper folder located in: C:\Users\"youruseraccount"\AppData\Roaming\

3.)Now delete the main sqldeveloper folder containing the actual SQL developer application files.This would be located wherever you initially unzipped the SQLDeveloper download.

4.)Download the latest version of SQL Developer and unzip wherever you like.

5.)Launch SQL developer and specify your JDK location.

6.)Copy your connections xml file to your roaming SQL Developer directory here: C:\Users\"youruseraccount"\AppData\Roaming\SQL Developer\systemXXXXXX)\o.jdeveloper.db.connection.xxxxxx

7.)Launch SQL Developer and your DBA view should now be available after selecting view -> DBA

Search for the file - windowinglayoutDefault.xml and delete it, and restart SQL Developer.

This file should be present inside a system folder at

windowuserPath\AppData\Roaming\SQL Developer\